Surgical table with displacement arrangement

ABSTRACT

A surgical table ( 1 ) comprises a longitudinal, at least partly radiolucent table top ( 2 ), a support structure ( 3 ) for the table top, said support structure including a lateral tilting mechanism ( 4 ) for providing lateral tilting movement to the table top ( 2 ), a base (B) for supporting the support structure and the table top, and lateral floating means ( 6 ) for allowing the table top a floating horizontal movement in lateral directions relative to the base ( 5 ). According to the invention said lateral floating means ( 6 ) are positioned below the lateral tilting mechanism ( 4 ) for permitting undisturbed lateral floating movement in horizontal as well as tilted positions of the table top ( 2 ).

This is a nationalization of PCT/SE01/00687 filed Mar. 29, 2001 andpublished in English.

FIELD OF THE INVENTION

This invention concerns a surgical table according to the preamble ofclaim 1.

DESCRIPTION OF PRIOR ART

Surgical tables of today provide movements in various dimensions such aselevation of the table and tilting about the longitudinal as well as thetransversal axis. These various movements are desirable for adoption toparticular operating situations and also, in case of a surgical tablehaving a radiolucent table top, i.a. for allowing freer X-ray imaging ofa particular body part. In particular, lateral tilt is used for allowingorgans to be imaged from different directions as desired and in somecases for displacing “loose” organs from each other or from “fixed”organs in order to obtain improved images.

EP-A2-0 923 922 concerns an operating table for surgical as well asimaging procedures. The table comprises a radiolucent table top andmeans for providing the table top with vertical lift, longitudinal tilt,lateral tilt and a four-way floating movement. A control switch isprovided which is effective to permit floating movement of the table topalong a horizontal axis and ineffective to permit floating movementalong a tilted axis. The table top is thereby totally prevented fromfloating movement when tilted both longitudinally and laterally, it isfree to float laterally, but not longitudinally when tilted onlylongitudinally, and it is free to float longitudinally but not laterallywhen tilted only laterally. When the table top is horizontal it is freeto float in either direction.

According to EP-A2-0 923 922, lateral movement of the table top is thusnot permitted when the table top is subjected to a lateral tilt and thereason for this is that when being laterally tilted there is a risk ofthe table top falling down to the lowermost position. Given that adultpatients often weigh well over 100 kg, free movability in lateraldirections could be dangerous for the patient as well as for thepersonnel, since it could jeopardise the stability of the entire table.The provision of automatic lock is therefore to be regarded as animportant safety measure according to this EP document.

When examining a patient using imaging equipment, the table top isusually floated with respect to the fixed imaging equipment in order toobtain the best images of the organ to be examined. In the prior artdevice according to EP-A2-0 923 922, however, it is difficult for thesurgeon to freely and flexibly scan the area around the organ of thepatient to be examined in a lateral tilted position of the table top. Inreal time imaging as well as in X-ray photography the surgeon can onlyuse the floating movement in the horizontal position of the table top,when freely locating and examining the patient. This is thus onlypossible before tilting the table top.

If free adjustment is desired or necessary after reaching a tiltedposition, the surgeon will either have to try to adjust the tilt or toadjust the position of the imaging equipment, which is typicallyarranged on a so called C-arm, partly enclosing the table top and thepart of the patient to be imaged. This is, however difficult and resultsin inexact positioning. This limitation with respect to thepossibilities of obtaining an overview of the patient's organs as wellas fine adjustment and flexibility has proved to be a serious drawbackof the prior art.

OBJECT AND SUMMARY OF THE FEATURES OF THE INVENTION

It is an object of the invention to overcome the drawbacks of the priorart and to provide a surgical table, which allows greater flexibilitywith respect to handling and applicability. This object is attained witha surgical table according to the above through the features of thecharacterising portion of claim 1.

These features make it possible to achieve lateral movement in lateraldirections of the table top also when the table top is subjected to alateral tilt. This is possible because the lateral floating means arepositioned so that they are unaffected by the lateral tilt. Noparticular power actuators are necessary for lateral movement even inlateral tilted positions of the table top since the lateral movement isunaffected by gravity forces. It should however be mentioned that theinvention does not exclude using power assisted float.

As to the inventive surgical table, the table with the table top in allpositions defines longitudinal directions along its longitudinalextension and lateral directions perpendicular thereto. The lateraltilting mechanism provides lateral tilting movement to the table top inparallel with the lateral directions. The lateral floating means isarranged such that it allows the table top floating horizontal movementin said lateral directions.

The invention brings along several advantages such as flexibility forthe surgeon, increased accuracy and possibility of quicker diagnosis,which could be crucial with respect to the well-being of the patient andthe success of the surgeon's efforts. No movement of the entire surgicaltable is necessary and no fine adjustment of the image C-arm.

It should be noted that lateral movability in lateral tilted positionsof the table top takes care of most imaging and operating situations.The table may or may not be arranged for allowing longitudinalmovability when the table top is subject to longitudinal tilt, e.g. bypower float means. Longitudinal tilt will, however, not influence thelateral movability. In most operating and imaging situations, however,the table top is not longitudinally tilted.

According to a preferred aspect of the invention, the lateral tiltingactuators are comprised of linkage mechanisms, which are arranged so asto obtain lateral tilting movement of the table top about an axis oraxes located above the table top. This gives a vertically compactsolution and makes it possible to tilt the table top and the patientaround a position close to the organ to be investigated.

It should be noted that tilting of the table top is important forseveral reasons. Longitudinal tilting around a transversal axis(Trendelenburg tilting) for example allows placing the head lower thanthe rest of the patient's body, which compensates for low blood pressurein case of trauma. As has been mentioned above, lateral tilting around alongitudinal axis allows imaging from chosen directions. It alsorelocates certain organs such as the bowls thereby freeing other organsfor examination. The invention makes it possible to fine adjust imagingin transversally tilted positions of the body, whereby the diagnosis maybe enhanced and made quicker.

The aspect where the lateral tilting actuators are attached to first andsecond frames guarantees the stability of the construction. The framesalso make it possible for a vertical carrier beam belonging to the basestructure to extend through the insides of the frames, whereby theelevation path of the table top may be extended in an advantageous way(see claim 14).

According to a further aspect, the lateral tilting actuators may becomprised of program controlled actuators. These actuators arepreferably located between first and second frames thereby guaranteeingthe stability of the construction.

According to one further aspect, the provision of one part of thelateral floating means on the first frame provides for a simple androbust construction.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantageous achievements are obtained from other aspects of theinvention, which will come clear from the following description ofembodiments with reference to the drawing, wherein:

FIG. 1 shows in a side view a surgical table according to the inventionbut with protective hoods covering the movement mechanisms,

FIG. 2 shows in a perspective view the table of FIG. 1 dismantled,

FIG. 3 shows a surgical table of FIG. 1 without the table top in an endview

FIG. 4 shows, in a perspective view, the column unit of a tableaccording to the invention,

FIG. 5 shows an alternative lateral tilt mechanism,

FIG. 6 shows a head support to be used with a table according to theinvention, and

FIG. 7 shows a directional wheel arrangement to be used with a tableaccording to the invention.

DESCRIPTION OF EMBODIMENTS

In FIG. 1 a surgical table 1 is shown having a table top 2 and a supportstructure 3 for providing the table top 2 with various movements.

The surgical table 1 is shown in FIG. 2 in a longitudinal as well as alateral tilted position of the table top 2. The table top 2 is at leastpartially translucent and is carried by a support structure, in generalindicated with 3. The support structure 3 includes a lateral tiltingmechanism 4, a column unit 5 and elements for allowing a four-way floatof the table top with respect to the column unit 5.

It is important, and it is to be noted, that the invention relates to asurgical table wherein the support structure and in particular thecolumn unit 5 in all working positions are located generally inside avertical area including the table top. This because of firstly stabilityreasons, since in use of the table stability is not jeopardised becauseheavy loads, such as from heavy patients, act directly verticallythrough the support structure and the column unit in the table accordingto the invention. Secondly for simplicity reasons, since theconstruction may be made straight forward, light-weight anduncomplicated because of advantageous load distribution and because ofthe fact that excess forces emanating from a heavy patient is avoided.Displacing the patient for imaging purposes may therefore beaccomplished without instability being induced. Thirdly foraccessibility reasons, since working on the table top is not obstructedin any position around the table because the support structure does notextend sideways in any direction to an extent worth mentioning from thevertical area including the table top.

The lateral tilting arrangement 4 includes two longitudinally separatedlinkage mechanisms each comprising a pair of links 7 which arepositioned in planes essentially perpendicular to the table top 2 and tothe longitudinal direction of the table top 2. The links are arranged soas to obtain a tilting movement of the table top 2 when actuatinghydraulic cylinders 8. The cylinders 8 are arranged essentiallydiagonally within the linkage mechanism which is a four link mechanismconsisting of the links 7 and transversal portions 9″ and 10″ of first 9and second 10 frames which constitute the bottom part and the top partrespectively of the lateral tilting arrangement.

The table top 2 is movable longitudinally with respect to the secondframe 10 by means of a longitudinal floating arrangement 15 which islockable so as to prevent unintentional movement of the table top.

A base B supports the surgical table 1 against the floor and is providedwith castors (one shown at 19) so as to allow rolling movement of thetable. The base B supports a vertical beam 16 having vertical guides 17such as guide grooves and/or rails for guiding and supporting avertically displaceable, partly sleeve shaped elevator member 25. At itstop this elevator member 25 carries a support frame 11 which ispivotable with respect thereto, and in particular around a pivot axis P.The support frame 11 surrounds the beam 16 and co-operates at its topwith the first frame 9 for lateral movement of the table top withrespect to the column unit 5.

This is accomplished according to the shown embodiment by a lateralfloating means 6 comprising elements allowing cooperation between thetransversal elements 11″ and 9″ of the respective frames 9 and 11, so asto allow lateral movement of the first frame 9 with respect to thesupport frame 11. These lateral or “floating” movement elements alsoinclude locking members (not shown) so as to achieve fixation betweenthese frames in desired positions.

The column unit 5 also carries a vertical lift actuator 14 in the formof a hydraulic twin cylinder, for providing a table top elevation. Thevertical lift actuator 14 acts between a bottom portion (not shown) ofthe beam 16 and, at its top, the elevator member 25 at the support framepivot axis P.

The column unit 5 also comprises longitudinal tilt actuators (only oneshown) 13, which extend between the bottom of the elevator member 25 anda position on the support frame which is off-set the position P forattachment of the lift actuator 14. Actuation of the actuators 13results in longitudinal tilt or Trendelenburg tilt of the support frame11 and thereby of the table top 2.

The base B also comprises floor locks, one of which being indicated at20. These locks are located at the right end on FIG. 2, which accordingto this aspect is defined as the column unit rear end 18. The floorlocks are positioned behind the castor 19 as seen in a direction fromthe right to the left on FIG. 1. This arrangement gives free way fromsaid direction to the castor 19, without risking that the floor locksblock the movements of the surgical table 1 when it is for examplerolled over an obstruction such as a door threshold. Also at the frontend of the column unit the floor locks are positioned behind thecastors, which can be best seen in FIG. 1.

Rails 23 at the bottom side of the table top 2 are provided forco-operation during longitudinal movements of the table top with guides24 and (not shown) locks on top of the second frame 10.

In FIG. 3 the surgical table 1 is shown in an end view Trendelenburgtilted and laterally tilted so as to best illustrate the lateral tiltingarrangement and the lateral floating elements but without the table top.As is clear from FIG. 3 the bottom ends of the links 7 are separated bya greater distance than the top ends of said links.

The relation between the lengths of the links, the distance between thebottom pivot points 26, 27 of the links 7 on the first frame 9 and thedistance between the top pivot points 28, 29 of the links on the secondframe 10 is calculated so as to obtain a four-link mechanism whereby adesired lateral tilting movement of the second frame and thereby thetable top is achieved when tilting is initiated. The result in operationof this arrangement in that actuation of one of (or both) the twohydraulic cylinders 8 tilts the table top 2 in such a way that itappears to be tilted around an axis A (or a cluster of axes) beinglocated above the table top.

It should be noted that the tilting movement is not necessarily aperfect rotational movement around one single axis A, and this is notimportant in this respect. It is however a great advantage to have thearticulation of the table top around an axis or axes located above thetable top since firstly this does not essentially displace the patientlaterally when the table top is laterally tilted. Hereby excess forceson the equipment is avoided.

Secondly, neither does the tilting displace the organ to be examinedessentially out of focus of an imaging device, which is typically usedfor real time imaging. Tilting laterally during simultaneous imaging cantherefore be provided more easily.

Bolts 48 on the second frame 10 act as motion stops for preventingover-centre tilting of frame 11 with respect to frame 9.

Further from FIG. 3, at the bottom side of the first frame 9, rails 21are arranged which co-operate for lateral movements of the table topwith guides 22 and (not shown) locks at the top of the support frame 11.The locks being able to fix the lateral float in any desired position.According to the invention, the lateral float elements are constantlypositioned horizontally, irrespective of the prevailing lateral tilt,because of the relative positioning of the devices with respect to eachother. This makes it possible to use horizontal float in laterallytilted as well as in untilted positions.

FIG. 4 shows the column unit without the base. The vertical beam is atits bottom provided with an attachment arrangement 31 for the twin liftcylinder 14. 30 indicates the arrangement for fastening the cylinder 14to the support frame pivot axis P. The twin cylinder arrangement simplyconsists of two cylinders which are fastened (or integrated) side byside with their respective pistons acting in opposite directions.Actuation of the twin cylinder 14 may be arranged such that both pistonsextend before the other or such that one of the pistons make a fullmovement before the second piston starts to move. In any case, the twincylinder arrangement provides for extended actuation length and reducedlength in the retracted position of the cylinder.

Further, one of the tilt cylinders 13 is shown with the lower attachmentpoint 32 on the bottom part of the elevator member 25 and with the topattachment point on the point PP on the support frame 11 at a distancefrom the support frame pivot point P

The invention may be modified within the scope of the annexed claims. Itis thus possible to use alternative lateral tilting mechanisms, such asfor example traditional tilting arrangements or program controlledactuators, which may be set for traditional tilting or for tiltingaround an axis above the table top, see the above in detail describedembodiments. In FIG. 5 the mechanism comprises two parallel actuators36, 37 and a diagonally placed actuator 38. By appropriate control ofthe movement of these actuators, the frame 10 may be made to performvarious chosen movements, not only movements similar to the onedescribed with respect to the previous embodiment (FIGS. 2 and 3) butalso other possibly desired movements.

FIG. 6 shows an adjustable head-rest 39 which is pivoted around an axisdefined by the shaft 40. The head-rest 39 is on each side supported by anormally locked, overload protected rotational joint 42 which isreleased by turning the shaft 40 by means of the slip-grip handle 41.Turning this handle clockwise allows moving the head rest clockwise andvice versa. The device 42 may for example include a double back-stopmechanism of a per se known kind. The device 42 is easily attached toside rails equipping the table top for admitting fast and easyattachment and removal.

In order to enhance handling of the table during transport, the supportstructure is preferably equipped with a centrally placed guide wheel 44(FIG. 7) which is arranged in a housing 47 and constantly in a planesubstantially in parallel with the longitudinal direction of the tabletop. This wheel 44 is preferably placed near the centre of gravity, asseen in a view from above, and may be lowered against the floor orretracted therefrom by means of an actuator 45 operating an axis 46.When lowered, the wheel 44 acts as a directional stabiliser and helpsrolling the table in desired directions also on slightly slopingsurfaces and prevents undesired sideway movements of the table duringtransportation.

Also the longitudinal tilt mechanism may be arranged otherwise even ifthe mechanism described with respect to FIGS. 2 and 3 is preferred.

It is further possible to use other floating means and to use othermechanical elements than frames, although the construction with theframes is preferred because of the stability of the construction, and ofthe possibility to allow passage of the vertical beam which allows avertically compact solution. In stead of frames, for example plateshaving essentially the same outside dimensions may be used. In thisrespect it is however preferred that at least the element being carriedby the elevator members is a frame (in the shown embodiment the supportframe 11) allowing passage of the vertical beam.

It is more preferred that also the bottom element of the lateral tiltmechanism 4 which co-operates with the support frame is also a frame (inthe shown embodiment the first frame 9) allowing passage of the verticalbeam.

It is most preferred that also the top element of the lateral tiltmechanism 4 is also a frame (in the shown embodiment the second frame10) allowing passage of the vertical beam.

Other elevator mechanisms may also come into question, such asconventional telescopic elevators.

The float as well as the tilt may be program controlled, e.g. togetherwith the vertical lift. For example it is possible to control verticallift and longitudinal tilt so as to achieve rotation around a chosenlongitudinal position of the table top. All hydraulic actuators may bereplaced with mechanical ones, for example electrically driven linearactuators. The tilt may be achieved by either electrical or hydraulicpower rotators co-operating with links or the like.

In the present text “comprising” is to be interpreted as “including”,i.e. part of open definitions. As an example “device comprising a firstelement” is to be interpreted such that the device also may includesecond, third etc. elements.

What is claimed is:
 1. A surgical table (1) comprising: a longitudinal,at least partly radiolucent table top (2) defining longitudinaldirections and lateral directions, a support structure (3) for the tabletop, said support structure including a lateral tilting mechanism (4)for providing a lateral tilting movement to the table top (2) inparallel with the lateral directions, a column unit (5) for supportingthe support structure and the table top, lateral floating means (6) forallowing the table top floating horizontal movement in said lateraldirections relative to the column unit (5), characterized in that saidlateral floating means (6) are positioned below the lateral tiltingmechanism (4) permitting undisturbed lateral movement in said lateraldirections in any table top position, tilted as well as horizontal. 2.The surgical table (1) according to claim 1, wherein the lateral tiltingmechanism (4) is comprised of at least two longitudinally separatedlinkage mechanisms, each comprising two links (7), which are extendingin a plane transverse to the table top (2), and which converge upwardsso as to obtain lateral tilting movement of the table top (2)essentially about an axis (A) or axes being located above the table top(2).
 3. The surgical table (1) according to claim 2, wherein the lateralfloating means (6) is comprised of at least two parallel rails (21) andmating guides (22).
 4. The surgical table (21) according to claim 1,wherein the lateral tilting mechanism (4) at the bottom is attached to afirst frame (9) and at the top end to a second frame (10), each framehaving longitudinal (9′, 10′) and transversal (9-′, 10-′) elements. 5.The surgical table (1) according to claim 4, wherein the transversalelements (9-′) of the first frame (9) are attached to the lateralfloating means (6) and the first frame (9) is thus laterally movablewith respect to the base (5).
 6. The surgical table (1) according toclaim 4, wherein longitudinal floating means (15) are provided betweenthe table top (2) and the second frame (10).
 7. The surgical table (1)according to claim 4 wherein the first frame (9) is capable ofsurrounding the top portion of the beam (16) in a vertically lowestposition of the table top (2) while maintaining floating and tiltingcapability.
 8. The surgical table (1) according to claim 7, wherein thesecond frame (10) is capable of surrounding the top portion of the beam(16) in a vertically lowest position of the table top (2) whilemaintaining floating and tilting capability.
 9. The surgical table (1)according to claim 1, wherein the lateral tilting mechanism (4)comprises program controlled actuators (36, 37, 38).
 10. The surgicaltable (1) according to claim 9 wherein the actuators (4) are operativebetween first (9) and second (10) frames having transversal andlongitudinal elements.
 11. The surgical table (1) according to claim 1,wherein portions (22) of the lateral floating means (6) are attached tolateral elements (11′-) of a support frame (11) which is attached to thecolumn unit (5).
 12. The surgical table (1) according to claim 11,wherein the support frame (11) is pivotally attached (P) to a verticallydisplaceable elevator member (25).
 13. The surgical table (1) accordingto claim 1 wherein longitudinal floating means (15) are provided betweenthe table top (2) and the support structure (3).
 14. The surgical table(1) according to claim 1, wherein the column unit (5) includes a tabletop elevator device (14, 16, 25).
 15. The surgical table (1) accordingto claim 14, wherein the column unit (5) comprises a vertical beam (16)with vertically extending guides (17) for a vertically displaceableelevator member (25).
 16. The surgical table (1) according to claim 1wherein the floating means (6, 15) are lockable in any chosen position.17. The surgical table (1) according to claim 1 wherein the base (5)comprises castors (19) at opposite ends thereof for movement relative toa floor, and manoeuvrable floor locks (20).
 18. The surgical table (1)according to claim 17, wherein, at one end of the base (5) defined as arear end (18), the floor locks (20) are positioned behind the rollers(19) as seen in a direction against said front end (18) so as not toobstruct movement over a door threshold or the like.
 19. The surgicaltable (1) according to claim 1, wherein the support structure isprovided with a central non-pivoting guide wheel (44), being optionallymade to contact the floor and act as a directional stabiliser.